MCQ'S CLASS 9 SAI
1Glucose, fructose and sucrose are the different forms of : (a) proteins (b) fats (c) carbohydrates (d) miner

2 On dissolving starch in hot water with stirring, it becomes : (a) transparent solution (b) translucent solution (c) opaque solution (d) suspension

 3 To prepare iron sulphide, by heating a mixture of iron filings and sulphur powder, we should use a : (a) Watch glass (b) China dish (c) Copper dish (d) Petri dish FeS (d) SO2

4Yellow coloured component in a mixture of Iron filing and sulphur is : (a) Iron (b) Sulphur (c) FeS (d) SO2

5 Crystals of copper sulphate are heated, they turn white. This colour change is due to :
(a) loss of copper ions (b) loss of sulphate ions (c) decomposition of copper sulphate (d) loss of water of crystallisation

(a) Illustrate with an example that physical and chemical changes can takes place together
.
 (b) Which of the following are chemical changes :
(i) Mixing of Iron filings and sand
 (ii) Growth of plant
 (iii) Rusting of Iron (iv) Freezing of water

  Define solid state of matter. State properties associated with this state.

 Illustrate with an example that evaporation cause cooling.

In which of the following substances you expect strongest and in which weakest force of attraction between the particles : alcohol, water, sodium chloride, carbondioxide. Give reason for your answer.

Write your observations when the following processes take place
 (a) an aqueous solution of sugar is heated to dryness.
 (b) a saturated solution of potassium chloride prepared at 60C is allowed to cool at room temperature.
 (c) a mixture of iron filings and sulphur powder is heated strongly.
 (d) A beam of light is passed through a colloidal solution.
 (e) dil – HCl is added to the mixture of iron and sulphur.

Describe an activity to show that air contains water vapours

(a) Define evaporation. Out of nylon and cotton clothes, which will be more comfortable during summer and why ? (b)
Is evaporation and boiling are same ? If not then why ?

Chemistry ( Chapter 1 and 2 ) MM.40
1. Why does a gas fill completely the vessel in which it is kept?
2. Why should we call a wooden table a solid?
3. Convert the following into Celsius scale: (i). 293 K (ii). 470K
4. Solids are normally not compressible. Why can a sponge be readily pressed?
5. A rubber band changes its shape when stretched. Can it be regarded as solid?
 6. Give reason: Water is liquid at room temperature whereas an iron almirah is solid?
7. Explain why there is no rise in temperature of a substance when it undergoes a change of state although it is still being heated?
 8. What is solid CO2?
9. How does pressure help in the liquefication of a gas?
 10. When sugar is dissolved in water, there is hardly an increase in volume. Which characterstic of matter is illustrated by this observation?
11. Two liquids differing in boiling point by at least 200 present in a mixture can be separated by fractional distillation. Explain.
 12. Fog and cloud are both colloidal in nature. How do they differ?
 13. Colloidal solutions show Tyndall effect but true solutions do not. Why?
14. How will check the purity of a pure chemical compound in the solid state?
 15. Sodium chloride contains two elements, but it is still a pure substance. Why?
16. Fresh air cannot be regarded as a pure substance. Why?
17. Butter is an example of one type of colloidal solution. Name it. Give reason for your choice.
18. Compare the particle sizes in a true solution, colloidal solution and suspension.
 19. A mixture of ethyl alcohol and water is homogeneous while that of oil and water is heterogeneous. Explain.
20. How can a saturated solution be made unsaturated?

CHEMISTRY CLASS 9 SAI
(a) Identify two non-metals from the following elements : i.e. Carbon, Sodium, Chlorine, Neon, Platinum.
(b) Name the appropriate methods to separate nitrogen from air.
(c) Identify dispersed phase and dispersion medium in foam and rubber.

Illustrate with an example that evaporation cause cooling

.Rahul’s mother mixed oil and water in kitchen by mistake. Rahul told her that he can separate the mixture. Name the technique used by Rahul and explain how he will do .

 Draw the diagram and write the principle of this technique.(a) Demonstrate with an activity that gases are highly compressible in nature.

(b) Giver reasons for the following :
 (i) A gas exerts pressure on the walls of the container.
 (ii) A gas fills the vessel in which it is kept
MCQ'S

.The presence of starch can be shown in which food material and using which reagent :
(a) apple juice and Iodine solution  (b) potato extract and safranin (c) apple juice and safranin (d) potato extract and Iodine solution.


A student added two drops of conc hydrochloric acid to adulterated dal in test tube A. Another student added a little sample to conc. hydrochloric acid in test tube B. They would observe.
 (a) appearance of pink colour in any test A (b) no change of colour in any test tube (c) appearance of pink colour in test tube B (d) appearance of pink colour in test tubes A and B


When a magnet is brought near iron sulphide taken in a watch glass ?
 (a) Particles of iron move towards the magnet. (b) Particles of iron sulphide move towards the magnet. (c) Particles of sulphur move towards the magnet. (d) No effect on Iron sulphide.


Students were asked to study the reaction between barium chloride and sodium sulphate. Four different generalisations are made
                     . Procedure                                                                              Observations
 (i) Mixed powder of barium chloride and sodium sulphate The colour of mixture changes to yellow (ii) Mixed solutions of barium chloride and sodium sulphate Thick white precipitate is formed
 (iii) Added solution of barium chloride to sodium sulphate powder Solution becomes turbid
(iv) Added solution of barium chloride to sodium sulphate solution No change is observed
 Choose the correct one :
(a) (i) (b) (ii) (c) (iii) (d) (iv)


In an experiment to determine the boiling point of water, mention two important precautions to be taken.

CLASS 7 PHYSICAL AND CHEMICAL CHANGES
1. State whether the following statements are true or false:
 (a) When a candle burns, both physical and chemical changes take place.
 (b) Anaerobic bacteria digest animal waste and produce biogas.
(c) Ships suffer a lot of damage though they are painted.
 (d) Stretching of rubber band is not a physical change.

 2. Melting of wax is a change where a solid changes to liquid state. Give one more such change which you observe in your surroundings.

3. What kind of change is shown by tearing of paper?

SHORT ANSWER QUESTIONS
4. Fill in the blanks in the following statements using the words given in the box.
 rusted, colourful, substance, chemical, physical, reversible, iron oxide, object
 (a) Making sugar solution is a ____________ change.
(b) A physical change is generally____________.
 (c) Grinding of wheat grain changes its size. It is a ____________ change.
 (d) Iron benches kept in lawns and gardens get____________. It is a _________ change because a new _________ is formed.

 5. Classify the following processes into physical or chemical changes:
 (i) Beating of aluminium metal to make aluminium foil.
 (ii) Digestion of food.
(iii) Cutting of a log of wood into pieces.
 (iv) Burning of crackers.

 6. Write word equations for two chemical reactions with the help of materials given in the box
. Air, copper sulphate, iron, vinegar, iron oxide, carbon dioxide, iron sulphate, copper, lime water, water

7. Explain the following:
(a) Lime water turns milky on passing carbon dioxide gas into it
. (b) Bubbles are produced when acetic acid is added to a solution of sodium hydrogencarbonate.

Nutrition in Animals
 MULTIPLE CHOICE QUESTIONS 1. Given below from (i) to (iv) are some food items.
 (i) Boiled and mashed potato (ii) Glucose solution (iii) A slice of bread (iv) Mustard oil Which of the above will give blue-black colour when tested with iodine?
 (a) (i) and (ii) (b) (i) and (iii) (c) (ii) and (iii) (d) (iii) and (iv)

 2. Which of the following pair of teeth differ in structure but are similar in function?
(a) canines and incisors. (b) molars and premolars. (c) incisors and molars. (d) premolars and canines.

 3. Read carefully the terms given below. Which of the following set is the correct combination of organs that do not carry out any digestive functions?
(a) Oesophagus, Large Intestine, Rectum (b) Buccal cavity, Oesophagus, Rectum (c) Buccal cavity, Oesophagus, Large Intestine (d) Small Intestine, Large Intestine, Rectum

4. The swallowed food moves downwards in the alimentary canal because of
 (a) force provided by the muscular tongue. (b) the flow of water taken with the food. (c) gravitational pull. (d) the contraction of muscles in the wall of food pipe.

 5. The acid present in the stomach
 (a) kills the harmful bacteria that may enter along with the food. (b) protects the stomach lining from harmful substances. (c) digests starch into simpler sugars. (d) makes the medium alkaline.

 6. The finger-like outgrowths of Amoeba helps to ingest food. However, the finger-like outgrowths of human intestine helps to
(a) digest the fatty food substances. (b) make the food soluble. (c) absorb the digested food. (d) absorb the undigested food.

 7. Read the following statements with reference to the villi of small intestine.
 (i) They have very thin walls. (ii) They have a network of thin and small blood vessels close to the surface. (iii) They have small pores through which food can easily pass. (iv) They are finger-like projections. Identify those statements which enable the villi to absorb digested food.
(a) (i), (ii) and (iv) (b) (ii), (iii) and (iv) (c) (iii) and (iv) (d) (i) and (iv)

 8. The false feet of Amoeba are used for
 (a) movement only. (b) capture of food only. (c) capture of food and movement. (d) exchange of gases only.

 9. The enzymes present in the saliva convert
 (a) fats into fatty acids and glycerol. (b) starch into simple sugars. (c) proteins into amino acids. (d) complex sugars into simple sugar

 10. Cud is the name given to the food of ruminants which is
 (a) swallowed and undigested. (b) swallowed and partially digested. (c) properly chewed and partially digested. (d) properly chewed and completely digested.

11. Choose the correct order of terms that describes the process of nutrition in ruminants.
 (a) swallowing → partial digestion → chewing of cud → complete digestion (b) chewing of cud → swallowing → partial digestion → complete digestion (c) chewing of cud → swallowing → mixing with digestive juices → digestion (d) swallowing → chewing and mixing → partial digestion → complete digestion



. VERY SHORT ANSWER QUESTIONS
12. Name the parts of the alimentary canal where
 (i) water gets absorbed from undigested food. (ii) digested food gets absorbed. (iii) taste of the food is perceived. (iv) bile juice is produced.

 13. Mark the following statements as True or False. If false, write the correct statements.
 (a) Tongue is attached to the roof of the mouth cavity at the back.
 (b) The large intestine is longer and wider than the small intestine of the human alimentary canal.
 (c) Mucus protects the stomach lining from damage.
 (d) All heterotrophs have a similar basic process of nutrition.

14. Choose the odd one out from each group and give reasons
. (i) liver, salivary gland, starch, gall bladder (ii) stomach, liver, pancreas, salivary gland (iii) tongue, absorption, taste, swallow (iv) oesophagus, small intestine, large intestine, rectum

 15. You were blindfolded and asked to identify the drinks provided in two different glasses. You could identify drink A as lime juice and B as bitter gourd juice. How could you do it inspite of being blindfolded?

16. Fill in the blanks with suitable words:
(a) The alimentary canal stretches from  _________ to __________.
 (b) Digestion of food starts in________ and gets completed in ___________.
 (c)_________ is the largest gland in the human body.

 17. Following statements describe the five steps in animal nutrition.
 Read each statement and give one word for each statement. Write the terms that describes each process.
(a) Transportation of absorbed food to different parts of body and their utilisation.
(b) Breaking of complex food substances into simpler and soluble substances.
 (c) Removal of undigested and unabsorbed solid residues of food from the body.
 (d) Taking food into the body.
 (e) Transport of digested and soluble food from the intestine to blood vessels.

CLASS 9 EVAPORATION (HINTS GIVEN IN THE END)
1Water as ice has a cooling effect, whereas water as steam may cause severe burns. Explain these observations.

2 Alka was making tea in a kettle. Suddenly she felt intense heat from the puff of steam gushing out of the spout of the kettle. She wondered whether the temperature of the steam was higher than that of the water boiling in the kettle. Comment

3.(a) Conversion of solid to vapour is called sublimation. Name the term used to denote the conversion of vapour to solid.
(b) Conversion of solid state to liquid state is called fusion; what is meant by latent heat of fusion?

4It is a hot summer day, Priyanshi and Ali are wearing cotton and nylon clothes respectively. Who do you think would be more comfortable and why?

5  You want to wear your favourite shirt to a party, but the problem is that it is still wet after a wash. What steps would you take to dry it faster?

6Comment on the following statements: (a) Evaporation produces cooling.
 (b) Rate of evaporation of an aqueous solution decreases with increase in humidity.

7Which condition out of the following will increase the evaporation of water? (a) Increase in temperature of water (b) Decrease in temperature of water (c) Less exposed surface area of water (d) Adding common salt to water


Multiple Choice Questions 1. Which one of the following sets of phenomena would increase on raising the temperature? (a) Diffusion, evaporation, compression of gases (b) Evaporation, compression of gases, solubility (c) Evaporation, diffusion, expansion of gases (d) Evaporation, solubility, diffusion, compression of gases

2. Seema visited a Natural Gas Compressing Unit and found that the gas can be liquefied under specific conditions of temperature and pressure. While sharing her experience with friends she got confused. Help her to identify the correct set of conditions (a) Low temperature, low pressure (b) High temperature, low pressure (c) Low temperature, high pressure (d) High temperature, high pressure

 3. The property to flow is unique to fluids. Which one of the following statements is correct? (a) Only gases behave like fluids (b) Gases and solids behave like fluids (c) Gases and liquids behave like fluids (d) Only liquids are fluids

4. During summer, water kept in an earthen pot becomes cool because of the phenomenon of (a) diffusion (b) transpiration (c) osmosis (d) evaporation

 5. A few substances are arranged in the increasing order of ‘forces of attraction’ between their particles. Which one of the following represents a correct arrangement? (a) Water, air, wind (b) Air, sugar, oil (c) Oxygen, water, sugar (d) Salt, juice, air

6. On converting 25°C, 38°C and 66°C to kelvin scale, the correct sequence of temperature will be (a) 298 K, 311 K and 339 K (b) 298 K, 300 K and 338 K (c) 273 K, 278 K and 543 K (d) 298 K, 310 K and 338 K

 7. Choose the correct statement of the following (a) conversion of solid into vapours without passing through the liquid state is called vapourisation. (b) conversion of vapours into solid without passing through the liquid state is called sublimation. (c) conversion of vapours into solid without passing through the liquid state is called freezing. (d) conversion of solid into liquid is called sublimation

. 8. The boiling points of diethyl ether, acetone and n-butyl alcohol are 35°C, 56°C and 118°C respectively. Which one of the following correctly represents their boiling points in kelvin scale? (a) 306 K, 329 K, 391 K (b) 308 K, 329 K, 392 K (c) 308 K, 329 K, 391 K (d) 329 K, 392 K, 308 K

 9. Which condition out of the following will increase the evaporation of water? (a) Increase in temperature of water (b) Decrease in temperature of water (c) Less exposed surface area of water (d) Adding common salt to water

10. In which of the following conditions, the distance between the molecules of hydrogen gas would increase? (i) Increasing pressure on hydrogen contained in a closed container (ii) Some hydrogen gas leaking out of the container (iii) Increasing the volume of the container of hydrogen gas (iv) Adding more hydrogen gas to the container without increasing the volume of the container

(a) (i) and (iii) (b) (i) and (iv) (c) (ii) and (iii) (d) (ii) and (iv)
HINT1
In case of ice the water molecules have low energy while in the case of steam the water molecules have high energy. The high energy of water molecules in steam is transformed as heat and may cause burns. On the other hand, in case of ice, the water molecules take energy from the body and thus give a cooling effect.
. The temperature of both boiling water and steam is 100°C, but steam has more energy because of latent heat of vapourisation.(a) The water will cool initially till it reaches 0°C, the freezing point. At this stage the temperature will remain constant till all the water will freeze. After this temperature would fall again.
4 The rate of evaporation increases with an increase of surface area because evaporation is a surface phenomenon. Also, with the increase in air speed, the particles of water vapour will move away with the air, which will increase the rate of evaporation.Conditions that can increase the rate of evaporation of water are (a) an increase of surface area by spreading the shirt (b) an increase in temperature by putting the shirt under the sun (c) increase the wind speed by spreading it under the fan.
.6 (a) Evaporation produces cooling as the particles at the surface of the liquid gain energy from the surroundings and change into vapour thereby producing a cooling effect.
 (b) Air around us cannot hold more than a definite amount of water vapour at a given temperature which is known as humidity. So, if the air is already rich in water vapour, it will not take up more water therefore, rate of evaporation of water will decrease.

1 In case of ice the water molecules have low energy while in the case of steam the water molecules have high energy. The high energy of water molecules in steam is transformed as heat and may cause burns. On the other hand, in case of ice, the water molecules take energy from the body and thus give a cooling effect.
The temperature of both boiling water and steam is 100°C, but steam has more energy because of latent heat of vapourisation